The Hospital Utilization Review Study's overall objective is to develop and evaluate methods for assisting UR committees in carrying out concurrent review. It is responsive to PSRO requirements to furnish health services in the most economical location possible. The study, cost-control oriented, concentrates on the appropriateness of location. It seeks to have hospital medical staffs establish their own explicit criteria for 1) location of services (services requiring a hospital level of care) as well as 2) appropriateness of services (the more familiar criteria of medical audit by diagnostic category). With these explicit criteria for location of services, the hospital could tell the intermediary or PSRO exactly what a patient requires in an acute hospital. Thus, hospitals can justify their operations and results to any outside agency. In three hospitals with concurrent UR systems, the study will develop and test methods of deciding on appropriate hospital use. Questions include: how to predict which patients to review and when; how to develop specific location criteria; how to select among alternative locations for patients; how to evaluate the UR review system on a periodic basis. After research, these UR mechanisms will be redesigned and offered as models applicable nationwide.